1. Field of the Invention
The present invention generally relates to the technical field of refuelling.
The present invention relates to a method and a system for refuelling, and a method and a device for detecting a limit fuel level and to a fuel pipe for a fuel container.
More specifically the invention relates to the technical field of spill free refuelling.
The present invention is especially suitable for the refuelling of vehicles. In such cases the fuel is sometimes inflammable and the fuel vapour is explosive. In addition to this, some fuels, like methanol, have toxic properties and the use in fuel cells is sensitive to contamination. Many vehicles are refuelled by non-professionals, i.e. persons that need an extremely safe and simple refuelling procedure and equipment. The following description of prior art, problems associated with such art and the purpose and features of the invention, will therefore, as non-limiting examples, to a certain extent be directed to this field of use. However, it should be pointed out that the invention may be used for other liquids and other refuelling objects, such as diesel oil for houses etc.
Refuelling is nowadays and will most probably also in the future be performed by non-professional operators, e.g. drivers of cars. There has also been a development towards other kinds of fuels, e.g. methanol for fuel cell use. This development calls for very secure, simple and easy-to-handle refuelling systems, considering e.g. toxic properties of such fuels. Also, extremely strict rules for use and handling of such fuels may be expected, if not already present.
2. Prior Art
Spill-free refuelling techniques are previously known. Thus, it is known to arrange a liquid-tight connection between a fuel dispensing nozzle and a fuel receiving coupling piece or nipple and to arrange an electric/electronic fuel level sensor arrangement in the fuel container. To activate the sensor arrangement, the arrangement has to be connected to a central control unit by means of a cable before refuelling. This means a quite complex procedure and several actions for the operator to remember, which leads to safety problems. Furthermore, the use of electric/electronic sensor arrangements requires quite complex and expensive arrangements to obtain a system, which is safe from a spark/fire point of view, when it comes to certain fuels, e.g. methanol.